Golang: Implementing a cron / executing tasks at a specific time

Question

I have been looking around for examples on how to implement a function that allows you to execute tasks at a certain time in Go, but I couldn't find anything.

I implemented one myself and I am sharing it in the answers, so other people can have a reference for their own implementation.

Answer 1

This is a general implementation, which lets you set:

• interval period
• hour to tick
• minute to tick
• second to tick

UPDATED: (the memory leak was fixed)

import (
"fmt"
"time"
)

const INTERVAL_PERIOD time.Duration = 24 * time.Hour

const HOUR_TO_TICK int = 23
const MINUTE_TO_TICK int = 00
const SECOND_TO_TICK int = 03

type jobTicker struct {
    timer *time.Timer
}

func runningRoutine() {
    jobTicker := &jobTicker{}
    jobTicker.updateTimer()
    for {
        <-jobTicker.timer.C
        fmt.Println(time.Now(), "- just ticked")
        jobTicker.updateTimer()
    }
}

func (t *jobTicker) updateTimer() {
    nextTick := time.Date(time.Now().Year(), time.Now().Month(), 
    time.Now().Day(), HOUR_TO_TICK, MINUTE_TO_TICK, SECOND_TO_TICK, 0, time.Local)
    if !nextTick.After(time.Now()) {
        nextTick = nextTick.Add(INTERVAL_PERIOD)
    }
    fmt.Println(nextTick, "- next tick")
    diff := nextTick.Sub(time.Now())
    if t.timer == nil {
        t.timer = time.NewTimer(diff)
    } else {
        t.timer.Reset(diff)
    }
}